The present invention relates to methods for removing a contaminant by a polyoxometalate-modified fabric or a polyoxometalate-modified cellulosic fiber from the gas or liquid phase. The invention further relates to polyoxometalate-modified fabrics and articles comprising a polyoxometalate-modified fabric.
Decreasing the potential danger of toxic gases has long been a significant issue. Offensive odors originating from cigarette smoke, sweat, exhaust gases, and rotten food in the work place, the home, and elsewhere are caused by thousands of gaseous components. Examples of deleterious and/or foul-smelling compounds include, but are not limited to, acetaldehyde, hydrogen sulfide, methyl mercaptan, ammonia, trimethylamine, and nicotine.
The goal is to fabricate and use self-deodorizing fabrics and cellulosic fibers in the form of clothing, furniture upholstery, curtains, carpets, or paper to remove or degrade gaseous or liquid toxic and/or malodorous compounds in the work place and home. Textiles produced in Japan are known to remove contaminants from the gas phase. Some of the Japanese textiles have carbonate anions or amines incorporated within the fiber. CLEAN GUARD, which is manufactured by Komatsu Seiren Co., LTD of Japan, contains finely divided ceramics and amphoteric oxides as the deodorizing components incorporated within the fabric. Smoklin(copyright), which is a cloth composed of polyacrylic yarn manufactured by Asahi Chemical Industry Company, can also remove contaminants from the gas phase. U.S. Pat. No. 5,603,927 to Fukumoto et al. discloses the incorporation of acid salts of aniline halides, amino benzoic acid, sulfanilamide or derivatives thereof, or aminoacetophenone into a porous carrier such as a fiber or cloth in order to remove offensive odors.
The prior art in this area, however, demonstrates a serious shortcoming, namely that the materials are effective only through stoichiometric physisorption or chemisorption processes based on acid-base, ion pairing (salt formation) and/or oxidation-reduction reactions. Because this technology is stoichiometric and not catalytic, it is not very practical and economical.
The incorporation of a polyoxometalate (herein referred to as xe2x80x9cPOMxe2x80x9d) into a fabric or cellulosic fiber in order to remove a contaminant from the gas phase has not been disclosed in the art. Furthermore, the prior art is very limited with respect to the use of a polyoxometalate-modified fabric or cellulosic fiber for the removal of a contaminant from the liquid phase. Gall et al. (Chem. Mat. 8, pp. 2523-2527, 1996) disclose the immobilization of H5PV2Mo10O40 on carbon cloth in order to determine the ability of H5PV2Mo10O40 to remove sulfur containing compounds from toluene. However, Gall et al. did not investigate the removal of sulfur containing compounds from the gas phase.
Typically, heteropoly and isopoly acids, which are subsets of polyoxometalates, are used as pigments and dyes when they are incorporated into a fabric. Japanese Patent Application No. JP 50136488 to Kakinuma et al. discloses contacting yarn with a heteropoly acid or tartaric acid to improve the lightfastness of the yarn. Japanese Patent No. JP 82014477 B discloses the lightfastness of yarn is improved when the yarn is contacted with an aqueous solution of phosphomolybdic acid.
JP 5179188, JP 61185568, and JP 62013464 disclose that heteropoly acids such as phosphotungstic acid, phosphomolybdic acid, silicomolybdic acid, silicotungstic acid, phosphotungstomolybdic acid, phosphovanadomolybdic acid, and their salts can be used as colorants and pigments for ink compositions. U.S. Pat. No. 3,947,332 to Vanderpool et al. disclose the synthesis of heteropoly acids containing tungsten or molybdenum and at least one other element having a positive valence from 2 to 7. The heteropoly acids disclosed in Vanderpool et al. can be used in printing inks and paper coloring.
U.S. Pat. No. 3,925,006 to Forschirm et al. discloses first contacting a cellulose ester with sodium tungstophosphate or sodium tungstosilicate followed by contacting the cellulose ester with a cationic dye. The sodium tungstophosphate and sodium tungstosilicate improve the uptake of the cationic dye into the cellulose ester. U.S. Pat. No. 4,444,592 to Ludwig discloses the preparation of a pigment that is the reaction product between a heteropoly acid and pararosaniline. The water insoluble pigment can be used in the textile arts. Chem. Rev. 1998, 98, pp. 359-387 to Katsoulis is a comprehensive review article that discloses the use of POMs as dyes and pigments.
Japanese Patent No. JP 71036516 B discloses a method for resin-treating textile goods containing cellulosic or hydrophobic fibers. The cellulosic fiber is treated with an isopoly or heteropoly acid. The resultant cellulosic fiber possesses increased soil-and-crease resistance and wash-and-wear properties. International Patent Application No. 94/20565 to Jackson et al. discloses contacting an aramid with an aqueous solution of a tungsten compound, preferably phosphotungstic acid and ammonium metatungstate, in order to decrease the flammability of textile articles. None of the references described above disclose the removal of a contaminant from the gas or liquid phase.
A POM-based fixed-bed catalytic reactor for the purification of gas in vents or passages has been disclosed in Japanese Patent Application No. 0435716 to Akio et al. This reactor involves a POM (H3PMo6W6O40) immobilized on a porous moulding of cordierite.
Japanese Patent Application No. 7251075 discloses the gas phase oxidation of unsaturated aldehydes to the corresponding carboxylic acid by a heteropoly acid catalyst containing molybdenum and vanadium. The catalyst is used in combination with carbon fibers. There is no disclosure in JP 7251075, however, for the removal of a contaminant from the gas or liquid phase.
In light of the above, it would be very desirable to have an article and a method of using an article for the removal of toxic and/or malodorous compounds without adding stoichiometric amounts of additives or compounds to the article. The present invention solves such a need in the art while providing surprising advantages. The present invention herein incorporates a catalytically active early-transition-metal oxygen anion cluster (polyoxometalate or POM) into textiles, fabrics, and cellulosic fibers, including the Japanese deodorizing fabrics described above, which greatly increases the ability of the fabric to remove toxic, offensive and/or odorous compounds from the gas and liquid phase.
In accordance with the purpose(s) of this invention, as embodied and broadly described herein, this invention, in one aspect, relates to a method for removing a contaminant from the gas phase, comprising contacting an article comprising a fabric and at least one polyoxometalate, wherein the polyoxometalate is incorporated in the fabric to produce a polyoxometalate-modified fabric, with the gas phase containing the contaminant.
The invention further relates to a method for removing a contaminant from the liquid phase, comprising contacting an article comprising a fabric and at least one polyoxometalate, wherein the polyoxometalate is incorporated in the fabric to produce a polyoxometalate-modified fabric, with the liquid phase containing the contaminant, with the proviso that when the fabric is carbon cloth, then the polyoxometalate is not H5PV2Mo10O40.
The invention further relates to a method for removing a contaminant from the gas phase or liquid phase, comprising contacting an article comprising a cellulosic fiber and at least one polyoxometalate, wherein the polyoxometalate is incorporated in the cellulosic fiber to produce a polyoxometalate-modified cellulosic fiber, with the gas phase or liquid phase containing the contaminant.
The invention further relates to a polyoxometalate-modified fabric, comprising a fabric and at least one polyoxometalate, wherein the polyoxometalate has the formula [VkMomWnNboTapMqXrOs]yxe2x88x92[A], wherein M is at least one f-block element or d-block element having at least one d-electron, wherein M is not vanadium, molybdenum, tungsten, niobium, or tantalum; X is at least one p-, d-, or f-block element, wherein X is not oxygen; k is from 0 to 30; m is from 0 to 160; n is from 0 to 160; o is from 0 to 10; p is from 0 to 10; q is from 0 to 30; r is from 0 to 30; s is sufficiently large that y is greater than zero; and y is greater than zero, wherein the sum of k, m, n, o, and p is greater than or equal to four; and the sum of k, m, and q is greater than zero, and A is a counterion, wherein the polyoxometalate is incorporated in the fabric, with the proviso that when A is a proton, the polyoxometalate is not the reaction product between [VkMomWnNboTapMqXrOs]yxe2x88x92[A] and a pararosaniline compound, with the further proviso that the polyoxometalate is not silicomolybdenic acid or its sodium salt, phosphomolybdenic acid, ammonium chromododecanemolybdenate, ammonium salt of hydrogen bexamolybdocobaltic acid, para-tungstic acid or its ammonium salt or sodium salt, meta-tungstic acid or its ammonium salt or sodium salt, phosphotungstic acid or its salt, silicotungstic acid or its salt, dodecane tungstodicobaltic acid or its salt, phosphotungstomolybdenic acid or its salt, or phosphovanadomolybdenic acid or its salt, with the further proviso that when the fabric is carbon cloth, the polyoxometalate is not H5PV2Mo10O40.
The invention further relates to an article comprising a polyoxometalate-modified fabric.
The invention further relates to a method of making a polyoxometalate-modified fabric comprising contacting the fabric with the polyoxometalate to produce the polyoxometalate-modified fabric.
Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.